ld/NEWS

   1 -*- text -*-
   2
   3 * Add support for the Freescale XGATE architecture.
   4
   5 * Add option -f FILE on AIX (for response file).
   6
   7 * Add support for the Renesas RL78 architecture.
   8
   9 * Add support for the Adapteva EPIPHANY architecture.
  10
  11 Changes in 2.22:
  12
  13 * --copy-dt-needed-entries is no longer enabled by default.  Instead
  14   --no-copy-dt-needed-entries is the default.
  15
  16 * INPUT_SECTION_FLAGS has been added to the linker script language
  17   to allow selection of input sections by section header section flags.
  18
  19 * Add support for the Tilera TILEPro and TILE-Gx architectures.
  20
  21 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
  22   sorting sections by numerical value of the GCC init_priority attribute
  23   encoded in the section name.
  24
  25 Changes in 2.21:
  26
  27 * Linker script expression evaluation is somewhat more sane.  This may
  28   break scripts that depend on quirks of the old expression evaluation.
  29
  30 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
  31   option --enable-leading-mingw64-underscores can be used on configure of
  32   bfd.
  33
  34 * Add support for the TMS320C6000 (TI C6X) processor family.
  35
  36 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
  37   with --as-needed option.
  38
  39 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
  40   to alias the import/export table name written in PE image.
  41
  42 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
  43   symbols from automatically being exported.
  44
  45 * Add support for the Renesas RX processor.
  46
  47 * Add support for alpha-vms target.
  48
  49 Changes in 2.20:
  50
  51 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
  52   GNU extension to the standard set of ELF symbol bindings.  The binding will
  53   be passed on to the dynamic linker which will make sure that in the entire
  54   process there is just one symbol with the given name and type in use.
  55
  56 * PE targets now support a GNU extension to allow the alignment of common
  57   common symbols to be specified.  This support uses custom options in
  58   the .drectve section, which will be disregarded by the native tools.
  59
  60 * PE targets now add primitive support for ELF version scripts; symbols
  61   are not versioned, but the local and global symbol visibility directives
  62   are respected when filtering symbols in auto-export mode.
  63
  64 * New option --no-export-dynamic to undo the effect of the -E and
  65   --export-dynamic options.
  66
  67 * ELF: --warn-alternate-em option to warn if an object has alternate
  68   ELF machine code.
  69
  70 * New script function REGION_ALIAS to add alias names to memory regions.
  71
  72 * PE targets no longer make use of the long section names PE extension to
  73   the COFF format when generating executable images, by default.  The old
  74   (slightly non-conformant) behaviour can still be invoked by using the
  75   new '--enable-long-section-names' command-line option.  It is also enabled
  76   automatically in the presence of un-stripped debug information, as GDB
  77   needs to be able to find the debug info sections by their full names.
  78
  79 * For GNU/Linux systems the linker will now avoid processing any relocations
  80   made against symbols of the STT_GNU_IFUNC type and instead emit them into
  81   the resulting binary for processing by the loader.
  82
  83 * --as-needed now links in a dynamic library if it satisfies undefined
  84   symbols in regular objects, or in other dynamic libraries.  In the
  85   latter case the library is not linked if it is found in a DT_NEEDED
  86   entry of one of the libraries already linked.
  87
  88 * Add a new command line option, -Ttext-segment ADDR, for ELF targets
  89   to set the address of the first byte of the text segment.
  90
  91 * Add support for Sunplus score architecture.
  92
  93 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
  94   allow fallback to old import table generation with null element prefix.
  95
  96 * Windows PE systems now support a new --exclude-modules-for-implib option,
  97   allowing users to partition object files and archive members between a DLL
  98   and its associated import library as they are generated during linking.
  99
 100 * Add support for Lattice Mico32 (lm32) architecture.
 101
 102 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 103   for Embedded-PIC code) option.
 104
 105 * Add to the PE/PE+ targets the support of two different kinds of
 106   pseudo-relocations.  They can be selected by the switches
 107   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 108   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 109   runtime pseudo relocation version one, for 64-bit the version two.
 110
 111 Changes in 2.19:
 112
 113 * Linker scripts support a new INSERT command that makes it easier to
 114   augment the default script.
 115
 116 * Linker script input section filespecs may now specify a file within an
 117   archive by writing "archive:file".
 118
 119 * The --sort-common switch now has an optional argument which specifies the
 120   direction of sorting.
 121
 122 * The M68K linker now supports multiple GOT generation schemes controlled via
 123   the --got=<type> command line option.
 124
 125 * The ARM EABI linker will now generate stubs for function calls to symbols
 126   that are too far away.  The placement of the stubs is controlled by a new
 127   linker command line option: --stub-group-size=N.
 128
 129 Changes in 2.18:
 130
 131 * Linker sources now released under version 3 of the GNU General Public
 132   License.
 133
 134 * ELF: New --build-id option to generate a unique per-binary identifier
 135   embedded in a note section.
 136
 137 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 138
 139 * -l:foo now searches the library path for a filename called foo,
 140   without converting it to libfoo.a or libfoo.so.
 141
 142 * Add a new command line option '--default-script=FILE' or '-dT FILE'
 143   which specifies a replacement for the built in, default linker
 144   script.
 145
 146 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 147   operator new and delete on the dynamic list, and --dynamic-list-data,
 148   builtin list for --dynamic-list, which puts global data symbols on the
 149   dynamic list.
 150
 151 * Add support for x86_64 PE+ target.
 152
 153 * Add support for Score target.
 154
 155 * ELF: Add --dynamic-list option to specify a list of global symbols
 156   whose references shouldn't be bound to the definition within the
 157   shared library, or a list of symbols which should be added to the
 158   symbol table in the executable.
 159
 160 * The default output section LMA has changed for allocatable sections from
 161   being equal to VMA, to keeping the difference between LMA and VMA the same as
 162   the previous output section in the same region.  This is a more useful
 163   default when using overlays and other cases where you specify an LMA
 164   differing from the VMA for some sections.
 165
 166 * New switch: --print-gc-sections to list any sections removed by garabge
 167   collection.
 168
 169 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 170   VFP11 coprocessors.
 171
 172 Changes in 2.17:
 173
 174 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 175
 176 * Modify the Linux linker search order to better match ld.so search order.
 177   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 178   searching the default directories, rather than vice versa.
 179   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 180
 181 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 182   passed directly to ld.
 183
 184 * Support for the Z80 processor family has been added.
 185
 186 * Add support for the "@<file>" syntax to the command line, so that extra
 187   switches can be read from <file>.
 188
 189 Changes in 2.16:
 190
 191 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 192   specification has been added via the --fix-v4bx command-line option.
 193
 194 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 195   for input files listed inside of it.
 196
 197 * A new command-line option, --sysroot, can be used to override the
 198   default sysroot location.  It only applies to toolchains that were
 199   configured using --with-sysroot.
 200
 201 * New linker script functions: ORIGIN() and LENGTH() which return information
 202   about a specified memory region.
 203
 204 * Port to MAXQ processor contributed by HCL Tech.
 205
 206 * Added SEGMENT_START to the linker script language to permit the user to
 207   override the base address for a segment from the command-line.
 208
 209 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 210   object.
 211
 212 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 213   language to permit sorting sections by section name or section
 214   maximum alignment.
 215
 216 * Added a new linker command line switch, --sort-section name|alignment,
 217   to sort sections by section name or maximum alignment.
 218
 219 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 220   should be added when a shared library comes from DT_NEEDED tags.
 221
 222 * Support for the crx-elf target added.
 223
 224 * Support for the sh-symbianelf target added.
 225
 226 * A new linker command line switch has been added which allows the hash table
 227   size to be set to a suitable prime value near to its argument.  This switch
 228   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 229   used, and --hash-size has not been used, then the default value will be set
 230   to 1021.
 231
 232 * Linker map files are now generated with an O(N) algorithm for finding symbols
 233   that are defined in each section.  This uses about 40% more memory for
 234   symbols than the old O(N^2) algorithm.  You can use the new
 235   --reduce-memory-overheads option to select the old algorithm; this option
 236   might also be used in the future to select similar tradeoffs.
 237
 238 Changes in 2.15:
 239
 240 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 241   be added only when a shared library is referenced.
 242
 243 * PE: --large-address-aware option to indicate executables support virtual
 244   addresses greater than 2 gigabytes.
 245
 246 * DWARF 2 support for i386pe added.
 247
 248 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 249   is defined before the statement where DEFINED is used.
 250
 251 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 252   Embedded-PIC code) is deprecated and will be removed in a future release.
 253
 254 * cr16c support added by NSC.
 255
 256 * m32r Linux (ELF) support added by Renesas.
 257
 258 * Improved linker's handling of unresolved symbols.  The switch
 259   --unresolved-symbols=<method> has been added to tell the linker when it
 260   should report them and the switch --warn-unresolved-symbols has been added to
 261   make reports be issued as warning messages rather than errors.
 262
 263 Changes in 2.14:
 264
 265 * Added support for Xtensa architecture.
 266
 267 * Added --with-sysroot configure switch to specify a target system root, for
 268   linking against a target filesystem image.
 269
 270 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 271   2.14) of silently accepting and linking in any files in an unknown binary
 272   file format.
 273
 274 * Added --no-omagic to undo the effects of the -N option.
 275
 276 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 277   DSP's contributed by Michael Hayes and Svein E. Seldal.
 278
 279 * Added --with-lib-path configure switch to specify default value for
 280   LIB_PATH.
 281
 282 * ARM port to QNX operating system added by Graeme Peterson.
 283
 284 * IP2K support added by Denis Chertykov.
 285
 286 Changes in 2.13:
 287
 288 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 289   and FR500 included.
 290
 291 Changes in version 2.13:
 292
 293 * DEC VAX ELF support, by Matt Thomas.
 294
 295 Changes in version 2.12:
 296
 297 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 298
 299 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 300
 301 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 302   production of copy relocs.  Warning: using this option may result in
 303   non-sharable applications.
 304
 305 * Support for -z combreloc in the ELF linker, which puts dynamic
 306   relocations against the same symbol together, so that dynamic linker
 307   can use an one-entry symbol lookup cache.
 308
 309 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 310
 311 Changes in version 2.11:
 312
 313 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 314
 315 * Support added for eliminating duplicate DWARF2 debug information by
 316   having the compiler generate the information in sections called
 317   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 318   linker then merges these sections together into the normal .debug_info
 319   section.
 320
 321 * The native ELF linker now searches the directories in DT_RUNPATH or
 322   DT_RPATH of a shared library for shared libraries needed by it.
 323
 324 * TI C54x support, by Timothy Wall.
 325
 326 * Added command line switch --section-start to set the start address of any
 327   specified section.
 328
 329 * Added ability to emit full relocation information in linked executables,
 330   enabled by --emit-relocs.  Some post-linkage optimization tools need
 331   this information in order to be able to correctly identify and perform
 332   symbol relative addressing in the event of changes in section contents
 333   (instructions being added or deleted, extending data sections, etc.)
 334
 335 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 336
 337 * Support for CRIS (Axis Communications ETRAX series).
 338
 339 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 340
 341 Changes in version 2.10:
 342
 343 * Added AT> to the linker script language to allow load-time allocation of
 344   sections into regions.
 345
 346 * Added garbage collection of unused sections, enabled by --gc-sections.
 347   It does require a bit of backend support; currently implemented are
 348   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 349   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 350   Others will ignore the option.
 351
 352 * Added SORT to the linker script language to permit sorting sections by file
 353   name or section name.
 354
 355 * Added EXTERN to the linker script language as an equivalent to the -u
 356   command-line option.
 357
 358 * Added ASSERT to the linker script language.
 359
 360 * Added EXCLUDE_FILE to the linker script language for further control over
 361   wildcard file names.
 362
 363 * Added -O option to optimize linker output (as of this writing, this only
 364   affects ELF shared library generation).
 365
 366 * The -e option now accepts a number as well as a symbol name.
 367
 368 * Added --no-undefined option to disallow undefined symbols when creating a
 369   shared library.
 370
 371 * The linker now issues a warning, not an error, for an undefined symbol when
 372   using -Bsymbolic; use the new --no-undefined option to get the old
 373   behaviour.
 374
 375 * Added --demangle and --no-demangle options.
 376
 377 Changes in version 2.9:
 378
 379 * Added SQUAD to the linker script language.
 380
 381 * New option --no-warn-mismatch.
 382
 383 * The MEMORY command now parses the attributes to determine where sections that
 384   are not placed in a specific memory region are placed.
 385
 386 Changes in version 2.8:
 387
 388 * Linker scripts may now contain shell wildcard characters for file and section
 389   names.
 390
 391 * The linker now supports symbol versions in ELF.
 392
 393 * The NOCROSSREFS command was added to the linker script language.
 394
 395 * The LOADADDR expression was added to the linker script language.
 396
 397 * MAX and MIN functions were added to the linker script language.
 398
 399 * The OVERLAY construct was added to the linker script language.
 400
 401 * New option --warn-section-align to warn when the address of an output section
 402   changes due to alignment of an input section.
 403
 404 * New options --filter/-F and --auxiliary/-f.
 405
 406 Changes in version 2.7:
 407
 408 * New option --cref to print out a cross reference table.
 409
 410 * New option --wrap SYMBOL.
 411
 412 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 413
 414 * Input sections assigned to the output section /DISCARD/ in the linker script
 415   are not included in the output file.
 416
 417 * The SunOS and ELF linkers now merge stabs debugging information which uses
 418   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 419   information generated.
 420
 421 Changes in version 2.6:
 422
 423 * When an ELF section name is representable as a C identifier (this is not true
 424 of most ELF section names), the linker will automatically define symbols
 425 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 426 beginning and the end of the section.  This is used by glibc.
 427
 428   Addendum: Current versions of the linker (at least for version 2.18 onwards
 429 and possibly much earlier as well) place two restrictions on this feature:  The
 430 symbols are only implemented for orphaned sections, not for explicitly placed
 431 sections and they are PROVIDEd rather than being defined.
 432
 433 * When an ELF section named .gnu.warning is encountered in an input file, the
 434 contents of the section are displayed as an error message, and the section is
 435 not copied into the output file.  This is used by glibc.
 436
 437 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 438 file, and the symbol SYMBOL is referenced by some object file, the contents of
 439 the section are displayed as an error message.  The section is not copied into
 440 the output file, unless doing a relocatable or shared link.  This is used by
 441 glibc.
 442
 443 * New options -split-by-reloc and -split-by-file.
 444
 445 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 446 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 447 will do so whenever there is an undefined symbol in the link and neither the -e
 448 nor the -r option was used.
 449
 450 * The -rpath option may be used on SunOS to set the list of directories to be
 451 searched at run time.  This overrides the default of building the list from the
 452 -L options.
 453
 454 * The COFF linker now combines debugging information for structs, unions, and
 455 enums, so that even if the same type is defined in multiple input files it will
 456 only be defined once in the output file.  The --traditional-format switch will
 457 prevent this optimization.
 458
 459 Changes in version 2.5:
 460
 461 * The linker now supports linking against SunOS shared libraries.  It still can
 462 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 463 generate shared libraries.
 464
 465 * The linker now supports linking against ELF shared libraries for the i386
 466 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 467 used to generate shared libraries.  Shared library generation is not well
 468 tested; please report any problems encountered.  The linker is now enabled for
 469 Solaris again.
 470
 471 * Eric Youngdale has contributed Linux support code, including linking against
 472 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 473
 474 * The ELF backend has been converted to the new linker code.  To use the new
 475 ELF linker, each particular target requires a relocation function.  So far,
 476 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 477 5), and HPPA ELF targets.
 478
 479 * The -( (--start-group) and -) (--end-group) options have been added to
 480 support searching a group of archives as though they were a single archive.
 481 This can also be used in a linker script, as GROUP ( files ).
 482
 483 * When a file is named on the command line, and the linker does not recognize
 484 it as an object file, the linker will now treat the file as a linker script
 485 file.  A linker script named in this way augments, but does not replace, the
 486 default linker script.
 487
 488 * The -warn-once option was added.  It causes the linker to only warn once per
 489 undefined symbol, rather than once per reference.
 490
 491 * The COFF backend has been converted to the new linker code.  As with ELF, to
 492 use the new linker, each particular target requires a relocation function.  So
 493 far, this function has been written for the i386, m68k, a29k and SH targets.
 494
 495 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 496 behaviour is available via --verbose.
 497
 498 Changes in version 2.4:
 499
 500 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 501   formats (so far), this should result in considerable savings in time
 502   and memory used while linking; slightly poorer performance than
 503   before for formats not converted yet.
 504
 505 * Command-line parsing is no longer done with flex.  This means
 506   oddball characters in filenames won't get treated as argument
 507   separators.
 508
 509 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 510
 511 * Mach i386 support, by David Mackenzie.
 512
 513 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 514   libraries are not yet supported).
 515
 516 * COFF shared libraries (as on SCO) should work as well.
 517
 518 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 519   forgot to note it.)  Some of their C library routines don't work when
 520   statically linked, and the GNU linker doesn't support dynamic linking yet.
 521
 522 Changes in version 2.3:
 523
 524 * Weak symbols are now supported.
 525
 526 * ELF support has been added.  The linker has been bootstrapped on
 527   UnixWare and Solaris.
 528
 529 * Alpha OSF/1 support has been added (non dynamic linking only).
 530
 531 Changes in version 2.2:
 532
 533 * The `bfd' library has been updated to reduce a.out-format string
 534   table size.  The effect of this is that files linked from many input
 535   files with duplicate symbols (`-g' debugging records, or identical
 536   static symbols) should be much smaller.
 537
 538 Changes in version 2.1:
 539
 540 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 541
 542 * There is now support for writing ECOFF files, so ld and the
 543   other utilities should work on Risc/Ultrix and Irix.
 544
 545 \f
 546 Local variables:
 547 fill-column: 79
 548 End: